The present invention relates generally to bulk material handling, and more particularly, to methods and systems for transferring, packaging, transporting, and otherwise handling bulk materials.
Typical processes for loading a typical soft-sided bulk material container with bulk material require supporting the soft-sided container using some sort of a support structure. FIG. 1 is a simplified schematic of a typical soft-sided container 100 supported in an external support structure. These structures are used in many forms and are of many different types, FIG. 1 showing an exemplary support structure 102 as a frame in which the container 100 is received. Such support structures are configured as structures in addition to the soft-sided container 100, and are in addition to equipment used for loading bulk materials 110 (shown in circle 112 and by arrow 114 as being loaded into the soft-sided container 100). The soft-sided container 100 is referred to as a “supported soft-sided container” when used with the support structure 102.
Exemplary bulk materials may include sand, minerals (e.g., salt and stone), agricultural materials (e.g., chemicals, fertilizers; bulk plastic pellets, whether new or recycled); waste materials (e.g., hazardous or non-hazardous), nuclear waste products loaded at controlled sites, landscaping or garden materials (e.g., compost, soil, bark) generally sold in small bags of manageable size, bulk grains (e.g., corn, feedstocks) and seeds. Such exemplary bulk materials may be mixed with other exemplary bulk materials, and each may be “wet”, as by being mixed with a liquid, such as water. One common feature of all such bulk materials is that for transport, the bulk material has no inherent shape and assumes the shape of the container in which the bulk material is received for transport, and this applies whether or not the bulk material is mixed with a liquid.
The supported soft-sided container 100 can be filled by scooping and dumping multiple front end loader bucket loads, or loads from a bucket of similar loading equipment or conveyor system until the supported soft-sided container is filled. Then, the supported soft-sided container is closed to prevent spillage. Finally, the filled soft-sided container can be moved, generally without the support structure 102.
Generally, when such filled soft-sided container is moved (as by the vertical upward movement out of the support structure 102), the contained bulk material tends to move downwardly under the force of gravity and cause the soft-sided sides to move laterally, referred to as bulging.
FIG. 2 is a typical, rectangular soft-sided bulk material container 100. The typical, rectangular soft-sided bulk material container 100 is filled with bulk material and has lost its rectangular shape as the sides are slumping downward and spreading (bulging) outward. The bulging soft-sided sides assume a more curved shape rather than a more desired rectangular shape.
During the vertical upward movement of the filled container 100 out of the support structure 102, the bulging sides are urged laterally and are pressed against the support structure 102, risking damage to the sides. Also, when many such soft-sided containers 100 are adjacent to each other, the bulging soft-sided curved sides of the adjacent containers are next to each other. These sides of the containers cause the adjacent containers to occupy more lateral space than containers without the curved (bulging) sides as shown in FIG. 2. This is disadvantageous not only for storage of these containers, but for transport, e.g., in rigid intermodal units or flatbed trucks or trailers.
In the past, attempts have been made to prevent the soft-sided sides from bulging during the vertical upward movement out of the support structure 102, and after the filled container has been removed from the external support structure. Various side-support structures have been secured to the sides inside the containers, e.g., between both opposite, or both diagonally-adjacent, sides of the containers (referred to as “fixed-in-place internal structures”). The length of the “fixed-in-place internal structures”) is an attempt to define a maximum value of a lateral space between the opposite sides, and is intended to avoid the lateral bulging of the opposite sides. However, when the exemplary dumping of the multiple front end loader bucket loads occurs into this soft-sided container having the “fixed-in-place internal structures”), the dumped bulk material often hits the “fixed-in-place internal structures”, and under the force of gravity acts on those “fixed-in-place internal structures”. The hitting and acting causes those “fixed-in-place internal structures” to curve downwardly and assume a curved shape extending to a lower location within the container. Because those internal structures are either rigid or non-stretchable, and as so secured to both the opposite, or adjacent, sides, the new curved shape of those structures is at the lower location and reduces the lateral (e.g., horizontal) length of those internal structures. Thus, the opposite soft-sided sides of the containers are moved toward each other, assume an inward (or reverse) bulge, and lessen the space between the opposite sides. The result is a bulge of the soft-sided walls above and below those structures, which is as disadvantageous as the outward bulge described above.
Whether such internal structures are secured to both of the opposite sides of the containers, or are secured to both of two adjacent sides of the soft-sided containers, the lateral bulging of both the inward or outward type may occur. As a result, bulging results when these containers are being filled, or lifted, or when they are stacked on top of each other. Moreover, in each case this bulging results from undesired gravitational action of the bulk material on the fixed-in-place internal structures.
What is needed, is a configuration of a soft-sided container by which difficult-to-avoid gravitational action of the bulk material does not cause the soft-sides to maintain their substantially vertical plan nor move or shift or expand laterally, neither inwardly toward each other nor outwardly away from each other, e.g., when the container is being filled with bulk material, or when the filled container is lifted off a support surface, or when the filled container is stacked on another soft-sided container.